NTPC, the country's largest utility, anticipates the private placement will initially raise 20 billion rupees ($251 million) and will be followed eventually by a spin-off of the green energy unit as a separate India-listed entity, the official said.

CPPIB, Petronas and Arcelormittal were not immediately available for comment.

The NTPC official was not authorised to speak to the press on this issue and could not be named.

($1 = 79.5960 Indian rupees)

(Reporting by Sudarshan Varadhan; editing by Barbara Lewis)